Video encoding device, video encoding method, video encoding program, video decoding device, video decoding method, and video decoding program

A picture coding method using a merge mode,

• the picture coding method comprising a normal merge mode derivation step of deriving a merging candidate list,
• the normal merge mode derivation step further including a merging candidate selecting step of adding a merge motion vector difference defined by a direction index indicating a direction and a distance index indicating a distance to a motion vector of the merging candidate list, and selecting one candidate from the merging candidate list as a selected merging candidate based on a merge index,
• wherein, when the motion vector of the selected merging candidate is smaller than a distance indicated by an arbitrary index of the distance index, the merging candidate selecting step includes at least one of setting a direction of the merge motion vector difference defined by the distance index indicating a larger distance than the motion vector of the selected merging candidate as a diagonal direction, and changing the distance indicated by the distance index.

A picture coding program using a merge mode,

• the picture coding program comprising a normal merge mode derivation step of deriving a merging candidate list,
• the normal merge mode derivation step further including a merging candidate selecting step of adding a merge motion vector difference defined by a direction index indicating a direction and a distance index indicating a distance to a motion vector of the merging candidate list, and selecting one candidate from the merging candidate list as a selected merging candidate based on a merge index,
• wherein, when the motion vector of the selected merging candidate is smaller than a distance indicated by an arbitrary index of the distance index, the merging candidate selecting step includes at least one of setting a direction of the merge motion vector difference defined by the distance index indicating a larger distance than the motion vector of the selected merging candidate as a diagonal direction, and changing the distance indicated by the distance index.

A picture decoding device using a merge mode,

• the picture decoding device comprising a normal merge mode derivation unit of deriving a merging candidate list,
• the normal merge mode derivation unit further including a merging candidate selector structured to add a merge motion vector difference defined by a direction index indicating a direction and a distance index indicating a distance to a motion vector of the merging candidate list, and select one candidate from the merging candidate list as a selected merging candidate based on a merge index,
• wherein, when the motion vector of the selected merging candidate is smaller than a distance indicated by an arbitrary index of the distance index, the merging candidate selector includes at least one of setting a direction of the merge motion vector difference defined by the distance index indicating a larger distance than the motion vector of the selected merging candidate as a diagonal direction, and changing the distance indicated by the distance index.

A picture decoding method using a merge mode,

• the picture decoding method comprising a normal merge mode derivation step of deriving a merging candidate list,
• the normal merge mode derivation step further including a merging candidate selecting step of adding a merge motion vector difference defined by a direction index indicating a direction and a distance index indicating a distance to a motion vector of the merging candidate list, and selecting one candidate from the merging candidate list as a selected merging candidate based on a merge index,
• wherein, when the motion vector of the selected merging candidate is smaller than a distance indicated by an arbitrary index of the distance index, the merging candidate selecting step includes at least one of setting a direction of the merge motion vector difference defined by the distance index indicating a larger distance than the motion vector of the selected merging candidate as a diagonal direction, and changing the distance indicated by the distance index.

A picture decoding program using a merge mode,

• the picture decoding program comprising a normal merge mode derivation step of deriving a merging candidate list,
• the normal merge mode derivation step further including a merging candidate selecting step of adding a merge motion vector difference defined by a direction index indicating a direction and a distance index indicating a distance to a motion vector of the merging candidate list, and selecting one candidate from the merging candidate list as a selected merging candidate based on a merge index,
• wherein, when the motion vector of the selected merging candidate is smaller than a distance indicated by an arbitrary index of the distance index, the merging candidate selecting step includes at least one of setting a direction of a merge motion vector difference defined by the distance index indicating a larger distance than the motion vector of the selected merging candidate as a diagonal direction, and changing the distance indicated by the distance index.